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Re: Flute making Apprentices

Posted: Thu Dec 28, 2017 9:42 am
by Geoffrey Ellis
I actually utilize a "reamer station" that I built at the back of my shop. It consists of a very substantial gear motor with a special tool holder attached to it for the reamers (the reamers have a hole through the shaft, so they slide into the holder and then are secured with a 1/4" steel pin through the shaft). The gear motor is set to 100 RPMs and it has massive amounts of torque. I usually work with billets that are still square. I don't use a lot of conventional flute woods, so I don't have to have them pre-bored or turned to facilitate drying. Because of this, I can pilot bore square stock which I then clamp into a set of v-blocks, securing them in between with two very large C-clamps. These provide "handles" for me to hold onto and I simply stand at the end of the reamer and feed the stock manually. It can be pretty physical at times (which is why I like the idea of using a series of shorter reamers). In the past, if I'm making a continuous cut with a long reamer, it takes a lot of strength to control the workpiece and not let the reamer snatch it away and spin it in mid-air! Fortunately the RPMs are slow enough to make this fairly safe.

Re: Flute making Apprentices

Posted: Mon Jan 01, 2018 9:32 am
by Mike Brennan
Interesting that Dave Copley mentioned taper pin reamers to get an idea how a multi-flute reamer would work. That's exactly what I use for Uilleann pipe chanters. I have a set of 6 taper pin reamers, #3 through #8, that I brazed to an extension and t-handle. They are overlapping sizes as mentioned earlier, and I can ream by hand with the t-handle holding the chanter with my other hand. Tedious and slow, but i'm not turning out production quantities. The smaller diameter of the chanter makes it easy to hold and doesn't require too much torque. I'm not sure it would work for a flute though.

Mike Brennan

Re: Flute making Apprentices

Posted: Mon Jan 01, 2018 2:41 pm
by Loren
Geoffrey, interesting reaming set-up you have. Must be nice to not have to deal with the seasoning process and all that goes with it, but then you have to stabilize the wood, so I there’s that. I’m wickedly allergic to most of the traditional woods now, so I’d have to go your route if I ever went back to instrument making. Anyway, the chain whip alleviates the need to resist the machine torque, so less of a workout, for those who are into that, lol.

Mike, Old School T handles, nice. Gets the job done. Don’t want to try that on a bass recorder, but we had some T handles around for the wee instruments.

Has anyone bothered to make expanding mandrels for holding reamed sections via drawbar on the headstock end?

Re: Flute making Apprentices

Posted: Mon Jan 01, 2018 3:21 pm
by Geoffrey Ellis
Loren wrote:Geoffrey, interesting reaming set-up you have. Must be nice to not have to deal with the seasoning process and all that goes with it, but then you have to stabilize the wood, so I there’s that. I’m wickedly allergic to most of the traditional woods now, so I’d have to go your route if I ever went back to instrument making. Anyway, the chain whip alleviates the need to resist the machine torque, so less of a workout, for those who are into that, lol.

Has anyone bothered to make expanding mandrels for holding reamed sections via drawbar on the headstock end?
I've been fortunate so far in not being allergic to tropical woods, but despite that I'm phasing them out completely. In this day and age, with CITIES, rainforest destruction and a number of other considerations I just decided to bend in the wind a bit.

I haven't tried holding sections of flute on an expanding mandrel yet, but it's a great idea. I recently got a bunch of 5C expanding soft collets and step collets so that I can machine them for specialty tasks like holding odd work pieces.

For example, I've recently added a stainless steel foot cap to my Pratten style flutes to help balance them. Because I don't use a foot joint and I've taken to using a fully lined head, the flutes felt a trifle top-heavy. So I decided to make a decorative metal foot with enough weight to fix the issue and it worked like a dream. But the problem with machining the foot caps was figuring out effective ways to hold the work while doing different tasks (they have to be counter bored in addition to doing an outside profile that includes a raised ring). Expanding collets and step collets to the rescue! They make everything easier and it would seem feasible to adapt some for holding flute sections. Fast, too, if doing production work. Here are a couple of pics...

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Re: Flute making Apprentices

Posted: Fri Aug 28, 2020 1:24 pm
by William Bryant
[Thread revival. - Mod]

Forgive me for resurrecting this thread, but I wanted to post where I found the reamer pics. (I just joined the forum.)

I am a nascent baroque flute maker who finds himself stuck at making reamers because the final result always warps. Here's what I've done so far.

1. Obtain a lathe and mill.
2. Make a taper attachment for the lathe.
3. Measure the inside bore of a flute I want to copy using a telescoping gauge, micrometer, etc. and plot the graph.
4. Set the taper attachment using simple math derived from my graph.
5. Obtain steel rods: O-1, Stressproof, unlabeled.
6. Turn tapers in the steel rods.
7. Test the tapered rods by sliding them into the bore of the flute I want to copy. (Perfect)
8. Mill out a slot in the tapered rod.

Warped! The reamer always "bananas" away from the slot.

Does anybody know how to make a reamer that doesn't warp?

(Pics of my process as soon as I figure out how to post them here.)

Re: Flute making Apprentices

Posted: Fri Aug 28, 2020 4:17 pm
by Geoffrey Ellis
So far the only reamers that I've made that don't warp have four cutting blades (attached thumbnail). A two-bladed reamer should be okay as well, because you are removing equal amounts of material from each side of the steel taper. Any D-profile reamer or variations on them are going to warp. There may be ways to harden the steel after you make the reamer, perhaps holding it under tension to keep it straight during the process (which I believe involves dipping the steel in some type of powder and then heating it to red hot, cooling it in a particular way, etc.). But this is going to have a big cost/pain-in-the-neck factor, even if you can find someone who offers the service.

My experience so far is that a warped reamer doesn't matter--it still cuts straight if you put a pilot on the end of the reamer (a short cylindrical section of the reamer that tracks on the pilot hole that you have drilled in the wood) the reamer will still cut straight. This may not be true in case of a really extreme warp, but I'd have to see what degree you are talking about.

Steel is like wood in terms of having the equivalent of grain-tension that gets released when you cut it. There are probably hardened steels that won't do this, but you don't want to try to make a reamer out of something like that! I tried making one from stainless steel one time, just for kicks, and it was a fiasco. Just too hard to machine.

This reamer below does not have a pilot on it because it is a four-bladed version and is perfectly straight.

Image






William Bryant wrote:[Thread revival. - Mod]

Forgive me for resurrecting this thread, but I wanted to post where I found the reamer pics. (I just joined the forum.)

I am a nascent baroque flute maker who finds himself stuck at making reamers because the final result always warps. Here's what I've done so far.

1. Obtain a lathe and mill.
2. Make a taper attachment for the lathe.
3. Measure the inside bore of a flute I want to copy using a telescoping gauge, micrometer, etc. and plot the graph.
4. Set the taper attachment using simple math derived from my graph.
5. Obtain steel rods: O-1, Stressproof, unlabeled.
6. Turn tapers in the steel rods.
7. Test the tapered rods by sliding them into the bore of the flute I want to copy. (Perfect)
8. Mill out a slot in the tapered rod.

Warped! The reamer always "bananas" away from the slot.

Does anybody know how to make a reamer that doesn't warp?

(Pics of my process as soon as I figure out how to post them here.)

Re: Flute making Apprentices

Posted: Fri Aug 28, 2020 9:51 pm
by an seanduine
Everything Geoffrey Ellis says is true. I would add some additional remarks.
One form of hardening is called ´Case-Hardening´. Essentially you use surface treatments (often powder) with heat, to increase the carbon content of the steel surface. The ancient process of making Wootz Steel in Northern India used a process similar to this by heat-soaking thin plates of low-carbon iron packed in charcoal for 36 to 48 hours at high heat. This is probably not readily accessible to you :D A quick and dirty method I have used in the shop is to make small cutters (like for example fraises for undercutting holes out of mild steel and then using a proprietary product like ´Casen-It´, available at welding shops), to harden the cutter teeth and make them last longer. I never used this on reamers, since their size precluded getting them uniformly heated all at one time. . .this makes the warping worse, and since the cutter is now hardened, straightening it more difficult :o The answer here is to use a step-drilled pilot hole. A mild steel reamer will then readily cut ´straight´. I have made tapered reamers for flute bodies, but most of my direct shop experience was with reamers for uilleann pipe chanters, where the cross section went from about 1/2 in. down to about .187 in. These are pretty ´wiggly´ so using step drilled pilot holes is imperative. So is patience. :twisted:

Bob

Re: Flute making Apprentices

Posted: Sat Aug 29, 2020 8:24 am
by Geoffrey Ellis
an seanduine wrote:Everything Geoffrey Ellis says is true. I would add some additional remarks.
One form of hardening is called ´Case-Hardening´. Essentially you use surface treatments (often powder) with heat, to increase the carbon content of the steel surface. The ancient process of making Wootz Steel in Northern India used a process similar to this by heat-soaking thin plates of low-carbon iron packed in charcoal for 36 to 48 hours at high heat. This is probably not readily accessible to you :D A quick and dirty method I have used in the shop is to make small cutters (like for example fraises for undercutting holes out of mild steel and then using a proprietary product like ´Casen-It´, available at welding shops), to harden the cutter teeth and make them last longer. I never used this on reamers, since their size precluded getting them uniformly heated all at one time. . .this makes the warping worse, and since the cutter is now hardened, straightening it more difficult :o The answer here is to use a step-drilled pilot hole. A mild steel reamer will then readily cut ´straight´. I have made tapered reamers for flute bodies, but most of my direct shop experience was with reamers for uilleann pipe chanters, where the cross section went from about 1/2 in. down to about .187 in. These are pretty ´wiggly´ so using step drilled pilot holes is imperative. So is patience. :twisted:

Bob
Good suggestion on the step drilling! I use this method whenever possible and it makes everything better. Of course you have to have the variety of drill sizes available to do it effectively, and on some very short pieces of wood (like the foot section of a flute, for example) it would be pointless because the taper over that distance is not significant.

I think hardened steel reamers would be the ideal if you had the means to do it conveniently, but I never have (at least not conveniently), and if you have it done for you the person needs to know what they are about or they can harden the warp permanently as Bob points out. I've gotten quite practiced at making reamers so I decided that I'd rather have to re-make a reamer every few years rather than bother with hardening. And there are ways to keep a nice, sharp cutting edge on the reamer during it's useful life. So to make things easy for me I use 41L40 steel, which is quite easy to machine for an alloy steel (thanks to the addition of lead, so don't inhale any of the metal dust if you sand it!). It can be heat-treated, but I don't bother.

Re: Flute making Apprentices

Posted: Sat Aug 29, 2020 2:58 pm
by William Bryant
Thanks for all the input, folks! very much appreciated.

I'm still trying to figure out how to post pictures. When I do, I'll upload a few and welcome any and all comments.

Thanks again,

Bill

Re: Flute making Apprentices

Posted: Sat Aug 29, 2020 7:39 pm
by PB+J
This is fascinating stuff

Re: Flute making Apprentices

Posted: Sun Aug 30, 2020 6:23 am
by Terry McGee
Careful. Pretty soon your normal friends will start to avoid personal contact, and all you'll have to fall back on for human contact are flute makers. And conversations about reamers, and boring, and partials reinforcement, tool steels, aerodynamic losses, socket cutters, scale lengths and so on. And then it's all downhill from there....

But, on the bright side, nothing is quite as much fun! As I'm sure Shakespeare said, "the flute's the thing...."

Re: Flute making Apprentices

Posted: Sun Aug 30, 2020 9:07 am
by Steve Bliven
Terry McGee wrote:...human contact
"Human contact", that's something the elders talk about around the fires....

Best wishes and wear your mask.

Steve

Re: Flute making Apprentices

Posted: Fri Oct 02, 2020 4:06 am
by MKE_Chris
FWIW, since the initial creation of this thread the Ballyfermot College of Further Education now has a traditional music performance course with an instrument-making strand, which when I last checked had the option of flute-making.

If you've got a couple years to spare...

https://www.bcfe.ie/courses/hnd-in-iris ... rformance/

Re: Flute making Apprentices

Posted: Fri Oct 02, 2020 5:25 am
by Terry McGee
Heh heh. I can't help but be taken back to Comhaltas workshops around the Fleadh in Listowel in 1974 where I was assured in serious tones that the music was severely on the decline. And here we are 46 years later, and young players are being tutored not only to play but to record and produce their recordings on Digital Work Stations. And make instruments if that's what drives them.

I don't know, young people these days. The world's going to hell in a handbasket.....

Hmmm. Where do you get these handbaskets?

Re: Flute making Apprentices

Posted: Tue Oct 06, 2020 3:08 pm
by benhall.1
Terry McGee wrote: The world's going to hell in a handbasket.....Hmmm. Where do you get these handbaskets?
Now, before I even look it up ... I've heard "going to hell in a handbasket" plenty of times, but wasn't it at one time "going to hell in a handcart"?